1. Field of Invention
The present invention relates to a method for coupling and uncoupling a self-propelled truck with a carrying truck on which articles and goods are loaded, and a device for effecting the same.
2. Description of Prior Art
Most of large industrial factories and storehouses are equipped with some self-propelled trucks and carrying trucks to be coupled therewith as an indoor automated transfer means for transferring goods and articles to a destination in production lines or a storage section.
In general, the self-propelled truck has a self-driving mechanism comprising driving wheels, a motor operatively connected to the driving wheels, and a photo-sensitive guidance; and control system, so that the truck moves by itself moves along a given path labelled by a light reflecting tape. This self-propelled truck is provided with a device for coupling and uncoupling it with a carrying truck which is adapted for carrying articles thereon.
However, a known device for coupling the self-propelled truck with the carrying truck is constructed by a pair of male and female engagement elements, one of them being provided at the self-propelled truck and another of them provided at the carrying truck. In most cases, those two separate engagement elements require a connecting pin for locking their mutual engagement to complete the coupling between the self-propelled truck with the carrying truck. As a result, there is a need and annoying labor on the part of workers to follow quite a few steps of engaging and disengaging the two engagement elements by inserting and removing the connecting pin thereto and therefrom.
Further, at each uncoupling point or each point where the articles are unloaded from the carrying truck, the self-propelled truck has to be stopped manually by a worker assigned only for that purpose. On the way to a terminal point, such stop points are set with a limited short stoppage time, considering an automated production line or continuous work line, and the workers must finish loading or unloading the articles or goods from the trucks during such limited stoppage time. The workers suffer from undesired tension state for long time and will fail to pursue the all loading or unloading process, causing a problem of unstable production line and also giving no guarantee to the safety of each worker.
The conventional coupler for coupling the self-propelled truck with the carrying truck(s) has been formed in a relatively large size containing a means for solving the above-stated problems. But, this results in enlarging the width of the path along which the coupled trucks moves and thus taking much of room in the space of the factory or storehouse.